Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of (S)-10-propargyl-pyrrolo-[2,1-c][1,4]benzodiazepine-5,11-dione.

The title compound, C(15)H(14)N(2)O(2), consists of pyrrole and benzodiazepine units linked to a propargyl moiety, where the pyrrole and diazepine rings adopt half-chair and boat conformations, respectively. The absolute configuration was assigned on the the basis of l-proline, which was used in the synthesis of benzodiazepine. In the crystal, weak C-H(Bnz)⋯O(Diazp) and C-H(Proprg)⋯O(Diazp) (Bnz = benzene, Diazp = diazepine and Proprg = proparg-yl) hydrogen bonds link the mol-ecules into two-dimensional networks parallel to the bc plane, enclosing R (4) (4)(28) ring motifs, with the networks forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.8%), H⋯C/C⋯H (25.7%) and H⋯O/O⋯H (20.1%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, C-H⋯O hydrogen-bond energies are 38.8 (for C-H(Bnz)⋯O(Diazp)) and 27.1 (for C-H(Proprg)⋯O(Diazp)) kJ†mol(-1). Density functional theory (DFT) optimized structures at the B3LYP/6-311†G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.